Koops Mailinglist is a very easy to setup and use mailing list script written in PHP. Email addresses have to be confirmed before they are activated. Option to unsubscribe. It includes an easy to use password protected admin interface with: bulk remove not confirmed email addresses older than 48 hours, list of subscribers with possibility to remove them, send mail to subscribers in HTML with WYSIWYG editor (FCKeditor, looks like MS Office 2003). Other features are: anti-flood protection, language files, installation script, mailer class (Swift) for more efficiency. XHTML and CSS valid.
